Organic/inorganic nanohybrids have attracted widespread interests due to their favorable properties and promising applications in biomedical areas. Great efforts have been made to design and fabricate versatile nanohybrids. Among different organic components, diverse polymers offer unique avenues for multifunctional systems with collective properties. This review focuses on the design, properties, and biomedical applications of organic/inorganic nanohybrids fabricated from inorganic nanoparticles and polymers. We begin with a brief introduction to a variety of strategies for the fabrication of functional organic/inorganic nanohybrids. Then the properties and functions of nanohybrids are discussed, including properties from organic and inorganic parts, synergistic properties, morphology-dependent properties, and self-assembly of nanohybrids. After that, current situations of nanohybrids applied for imaging, therapy, and imaging-guided therapy are demonstrated. Finally, we discuss the prospect of organic/inorganic nanohybrids and highlight the challenges and opportunities for the future investigations.

Infections caused by multidrug resistant bacteria are still a serious threat to human health. It is of great significance to explore effective alternative antibacterial strategies. Herein, carbon–iron oxide nanohybrids with rough surfaces (RCF) are developed for NIR-II light-responsive synergistic antibacterial therapy. RCF with excellent photothermal property and peroxidase-like activity could realize synergistic photothermal therapy (PTT)/chemodynamic therapy (CDT) in the NIR-II biowindow with improved penetration depth and low power density. More importantly, RCF with rough surfaces shows increased bacterial adhesion, thereby benefiting both CDT and PTT through effective interaction between RCF and bacteria. In vitro antibacterial experiments demonstrate a broad-spectrum synergistic antibacterial effect of RCF against Gram-negative Escherichia coli (E. coli), Gram-positive Staphylococcus aureus (S. aureus), and methicillin-resistant Staphylococcus aureus (MRSA). In addition, satisfactory biocompatibility makes RCF a promising antibacterial agent. Notably, the synergistic antibacterial performances in vivo could be achieved employing the rat wound model with MRSA infection. The current study proposes a facile strategy to construct antibacterial agents for practical antibacterial applications by the rational design of both composition and morphology. RCF with low power density NIR-II light responsive synergistic activity holds great potential in the effective treatment of drug-resistant bacterial infections.

The efficacy of cardiac regenerative strategies for myocardial infarction (MI) treatment is greatly limited by the cardiac microenvironment. The combination of reactive oxygen species (ROS) scavenging to suppress the oxidative stress damage and macrophage polarization to regenerative M2 phenotype in the MI microenvironment can be desirable for MI treatment. Herein, melanin nanoparticles (MNPs)/alginate (Alg) hydrogels composed of two marine-derived natural biomaterials, MNPs obtained from cuttlefish ink and alginate extracted from ocean algae, are proposed. Taking advantage of the antioxidant property of MNPs and mechanical support from injectable alginate hydrogels, the MNPs/Alg hydrogel is explored for cardiac repair by regulating the MI microenvironment. The MNPs/Alg hydrogel is found to eliminate ROS against oxidative stress injury of cardiomyocytes. More interestingly, the macrophage polarization to regenerative M2 macrophages can be greatly promoted in the presence of MNPs/Alg hydrogel. An MI rat model is utilized to evaluate the feasibility of the as-prepared MNPs/Alg hydrogel for cardiac repair in vivo. The antioxidant, anti-inflammatory, and proangiogenesis effects of the hydrogel are investigated in detail. The present study opens up a new way to utilize natural biomaterials for MI treatment and allows to rerecognize the great value of natural biomaterials in cardiac repair.

Because of the abuse of antibiotics and threats of antibiotic resistance, bacterial infection is still one of the most difficult issues to be resolved. Thus, it is of great significance to explore novel antibacterial agents. In this paper, we investigated a type of silica-coated gold–silver nanocages (Au–Ag@SiO2 NCs) as antibacterial candidates. Their intrinsic characteristics of photothermal property and sustained release of Ag ions were fully exploited for near-infrared (NIR)-induced combined anti-infective therapy. The broad-spectrum antibacterial property of the as-prepared Au–Ag@SiO2 NCs was confirmed in vitro against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli). In addition, Au–Ag@SiO2 NCs exhibit effective treatment of the S. aureus biofilm with the assistance of NIR irradiation. More importantly, we assessed the in vivo antibacterial efficacy of Au–Ag@SiO2 NCs against S. aureus, which demonstrated sustainably enhanced therapeutic effects on a rat model with wound infection.

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stability, biodegradability, ease of functionalization, and compromised toxicity. [1,2] Notably, polysaccharide/inorganic nanohybrids are considered ideal candidates as multifunctional platforms to combine the virtues of polysaccharides and intriguing inorganic nanoparticles. [3] Favorable synergistic properties arising from their integration could also be anticipated. [4] Recently, a variety of polysaccharide/inorganic nanohybrids have been fabricated via a nonsolvent-aided counterion complexation method while the morphology was limited to symmetrical spheres. [5-8] It is still a great challenge to obtain a controlled synthesis of a series of polysaccharide/ inorganic nanohybrids with adjustable morphologies to integrate the advantages of both components. On the other hand, unsymmetrical nanoparticles, especially Janus nanoparticles (JNPs), have attracted widespread interest since the morphology of nanoparticles greatly influences their properties and interactions with biological systems. [4,9,10] Compared with symmetrical core-shell-structured hybrid nanoparticles, JNPs demonstrate improved magnetic, optical, and drug-loading properties with more exposed areas of the components to maintain their characteristics. [11-13] Moreover, Near-infrared (NIR) light-responsive JNPs are also found to realize enhanced photothermal effect and penetration in tumors through self-propulsion, which is driven by the temperature gradient across the Janus boundary. [14-16] In these examples, photothermal gold nanoparticles including gold shells and stars were usually employed as a component of JNPs to realize active motion under NIR irradiation. On the other hand, gold nanorods are intriguing due to their tunable optical properties with different aspect ratios, which could be utilized to optimize photothermal performance and selective release of DNA by laser irradiation at different wavelengths. [17,18] However, distinct gold nanorods responsive to specific wavelengths of NIR light are still not well exploited in the fabrication of JNPs with enhanced photothermal performance. Gene therapy is considered a promising therapeutic modality to complement the limited light penetration of photothermal The unsymmetrical morphology and unique properties of Janus nanoparticles (JNPs) provide superior performances for biomedical applications. In this work, a general and facile strategy is developed to construct a series of symmetrical and unsymmetrical chitosan/gold nanoparticles. Taking advantage of the active motion derived from Janus structure, selective surface functionalization of polysaccharide domain, and photothermal effect of gold nanorods, Janus chitosan/gold nanoparticles (J-Au-CS) are selected as a model system to construct Janus-structured chitosan/gold nanohybrids (J-ACP). Near-infrared (NIR)-responsive J-ACP composed of polycationic chitosan nanospheres and PEGylated gold nanorods hold great potential to realize photoacoustic (PA) imaging-guided complementary photothermal therapy (PTT)/gene therapy for breast cancer. The morphol...

The protumoral and immunosuppressive tumor microenvironments greatly limit the antitumor immune responses of nanoparticles for cancer immunotherapy. Here, the intrinsic immunomodulatory effects of orchestrated nanoparticles and their ability to simultaneously trigger tumor antigen release, thereby reversing immunosuppression and achieving potent antitumor immunity and augmented cancer therapy, are explored. By optimizing both the composition and morphology, a facile strategy is proposed to construct yolk–shell nanohybrids (Fe3O4@C/MnO2‐PGEA, FCMP). The intrinsic immunomodulatory effects of FCMP are utilized to reprogram macrophages to M1 phenotype and induce the maturation of dendritic cells. In addition, the chemical, magnetic, and optical properties of FCMP contribute to amplified immunogenic cell death induced by multiaugmented chemodynamic therapy (CDT) and synergistic tumor treatment. Taking advantage of the unique yolk–shell structure, accurate T1‐T2 dual‐mode magnetic resonance imaging can be realized and CDT can be maximized through sufficient exposure of both the Fe3O4 core and MnO2 shell. Potent antitumor effects are found to substantially inhibit the growth of both primary and distant tumors. Furthermore, the strategy can be extended to the synthesis of other yolk–shell nanohybrids with tailored properties. This work establishes a novel strategy for the fabrication of multifunctional nanoplatforms with yolk‐shell structure for effective cancer therapy with immunomodulation‐enhanced antitumor immunity.

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